Perception: Object Recognition

Question 1

What is the Gestalt Theory/?

Answer 1

• Focus is on the whole object vs individual parts
• resurrected mental processed as a viable object of study vs just observable things by behaviourist
• who visual percept is more than the sum of its parts

Question 2

What does perception refer to?

Answer 2

our ability to extract meaning from sensory input

- audition, taste etc

Question 3

What sense dominates research on perception?

Answer 3

visual - since vision alone accounts for 50% of all neurons in our cortex

Question 4

We have more than 5 sense! What is it?

Answer 4

Proprioception

- constructive process which makes sense of all the incoming info

Question 5

What is the typical explanation for how the visual system works?

Answer 5

image received upside down and the cognitive system constructs perception

Question 6

What did Tootell et al in 1982 find when he pinned monkeys eyes open and removed their visual cortex?

Answer 6

• when visual cortex taken out, image they were shown did not match the image in RL
  = visual cortex has near accurate representation of external world

Question 7

why is there a blind spot the size of an orange in our visual cortex?

Answer 7

channel to connect to brain

Question 8

What do veins do to our vision?

Answer 8

distort our vision

Question 9

What is our visual acuity like?

Answer 9

Concentrated near the front of our eyes and colours fade further behind

Question 10

What is the binocular effect?

Answer 10

left and right visual field process separately

Question 11

What are the separate pathways to forming a visual image?

Answer 11

1. Dorsal pathway - making sense of sensory, location

2. Ventral pathway - what do you see, facts

Question 12

What is the 3 stage model of object recognition?

Answer 12

1. local features - edge/ contrast
2. shape representation - gestalt principle. feature integration
3. Object representation - bias about what an object should look like

Question 13

Why is it important to separate object recognition into stages?

Answer 13

allows us to identify what levels object recognition may have gone wrong/ why

Question 14

What are illusory contours?

Answer 14

• consequence of our visual perception imposing organisation
• laws of “good continuation” + “closure”
• proximity = see groups rather than separate lines
• similarity = see them in rows

Question 15

What are the differences between primitive and position in shape perception?

Answer 15

• primitive = edges, orientations

- position = features of what we are seeing

Question 16

What is symbolic primitive?

Answer 16

picture formed to make sense of a shape

- TOP down processing used to group collections of primitives together = lines/ curves etc

Question 17

What are the 3 models of Object Recognition?

Answer 17

1. Template matching prototype theory
2. Feature analysis
3. Recognition by components

Question 18

Explain the template matching prototype theory

Answer 18

• stimulus is compared to a set of templates that you already have stored in your memory
• stimulus need to fit exactly to template
• issue with different handwriting styles

Question 19

Explain the Feature-analysis theory

Answer 19

Visual stimulus composed of small number of characteristics/ components

• R = curved component, vertical like etc
• good for different handwriting
• but what about spatial relationships/ complex objects

Question 20

Explain the Recognition by components theory

Answer 20

• recognition of 3D shapes
• geons ( components like in feature analysis)
• 3 geons = enough
• viewer centered approach - what about the object from different angles
• when termination points removed = impaired object recognition